Dihydroxybenzoic acids are aromatic compounds consisting of a phenolic ring and a carboxylic acid. The six main compounds are structurally similar and are difficult to separate in reverse-phase HPLC. The can be separated by using a mixed-mode Newcrom B column with the mobile phase having either methanol (MeOH) or acetonitrile (ACN) as an organic modifier having different retention characteristics. Using the gradient of organic modifier, water and sulfuric acid (H2SO4) as buffer, dihydroxybenzoic acids can be separated and UV detected at 250nm.
| Column | Newcrom B, 4.6×150 mm, 5 µm, 100A |
| Mobile Phase | MeCN |
| Buffer | H2SO4 |
| Flow Rate | 1.0 ml/min |
| Detection | UV, 250 nm |
| Class of Compounds |
Drug, Acid, Hydrophilic, Ionizable, Vitamin, Supplements |
| Analyzing Compounds | 3.4-dihydroxybenzoic acid, 3.5-dihydroxybenzoic acid,2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid |
Application Column
Newcrom B
The Newcrom columns are a family of reverse-phase-based columns. Newcrom A, AH, B, and BH are all mixed-mode columns with either positive or negative ion-pairing groups attached to either short (25 Å) or long (100 Å) ligand chains. Newcrom R1 is a special reverse-phase column with low silanol activity.
Select options2,4-Dihydroxybenzoic Acid
2,5-Dihydroxybenzoic Acid
2,6-Dihydroxybenzoic acid
3,4-Dihydroxybenzoic Acid
3,5-Dihydroxybenzoic Acid
